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drivers/scsi/scsi_debug.c: resolve sg buffer const-ness issue

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do_device_access() takes a separate parameter to indicate the direction of
data transfer, which it used to use to select the appropriate function out
of sg_pcopy_{to,from}_buffer().  However these two functions now have

So this patch makes it bypass these wrappers and call the underlying
function sg_copy_buffer() directly; this has the same calling style as
do_device_access() i.e.  a separate direction-of-transfer parameter and no
pointers-to-const, so skipping the wrappers not only eliminates the
warning, it also make the code simpler :)

[akpm@linux-foundation.org: fix very broken build]
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Dave Gordon 2015-06-30 14:58:57 -07:00 committed by Linus Torvalds
parent 2a1bf8f93b
commit 386ecb1216
3 changed files with 10 additions and 11 deletions
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12
drivers/scsi/scsi_debug.c
View file

@ -2363,17 +2363,13 @@ do_device_access(struct scsi_cmnd *scmd, u64 lba, u32 num, bool do_write)
u64 block, rest = 0; u64 block, rest = 0;
struct scsi_data_buffer *sdb; struct scsi_data_buffer *sdb;
enum dma_data_direction dir; enum dma_data_direction dir;
size_t (*func)(struct scatterlist *, unsigned int, void *, size_t,
off_t);
if (do_write) { if (do_write) {
sdb = scsi_out(scmd); sdb = scsi_out(scmd);
dir = DMA_TO_DEVICE; dir = DMA_TO_DEVICE;
func = sg_pcopy_to_buffer;
} else { } else {
sdb = scsi_in(scmd); sdb = scsi_in(scmd);
dir = DMA_FROM_DEVICE; dir = DMA_FROM_DEVICE;
func = sg_pcopy_from_buffer;
} }
if (!sdb->length) if (!sdb->length)
@ -2385,16 +2381,16 @@ do_device_access(struct scsi_cmnd *scmd, u64 lba, u32 num, bool do_write)
if (block + num > sdebug_store_sectors) if (block + num > sdebug_store_sectors)
rest = block + num - sdebug_store_sectors; rest = block + num - sdebug_store_sectors;
ret = func(sdb->table.sgl, sdb->table.nents, ret = sg_copy_buffer(sdb->table.sgl, sdb->table.nents,
fake_storep + (block * scsi_debug_sector_size), fake_storep + (block * scsi_debug_sector_size),
(num - rest) * scsi_debug_sector_size, 0); (num - rest) * scsi_debug_sector_size, 0, do_write);
if (ret != (num - rest) * scsi_debug_sector_size) if (ret != (num - rest) * scsi_debug_sector_size)
return ret; return ret;
if (rest) { if (rest) {
ret += func(sdb->table.sgl, sdb->table.nents, ret += sg_copy_buffer(sdb->table.sgl, sdb->table.nents,
fake_storep, rest * scsi_debug_sector_size, fake_storep, rest * scsi_debug_sector_size,
(num - rest) * scsi_debug_sector_size); (num - rest) * scsi_debug_sector_size, do_write);
} }
return ret; return ret;

3
include/linux/scatterlist.h
View file

@ -265,6 +265,9 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
unsigned long offset, unsigned long size, unsigned long offset, unsigned long size,
gfp_t gfp_mask); gfp_t gfp_mask);
size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
size_t buflen, off_t skip, bool to_buffer);
size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents, size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents,
const void *buf, size_t buflen); const void *buf, size_t buflen);
size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents, size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents,

6
lib/scatterlist.c
View file

@ -650,9 +650,8 @@ EXPORT_SYMBOL(sg_miter_stop);
* Returns the number of copied bytes. * Returns the number of copied bytes.
* *
**/ **/
static size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
void *buf, size_t buflen, off_t skip, size_t buflen, off_t skip, bool to_buffer)
bool to_buffer)
{ {
unsigned int offset = 0; unsigned int offset = 0;
struct sg_mapping_iter miter; struct sg_mapping_iter miter;
@ -689,6 +688,7 @@ static size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents,
local_irq_restore(flags); local_irq_restore(flags);
return offset; return offset;
} }
EXPORT_SYMBOL(sg_copy_buffer);
/** /**
* sg_copy_from_buffer - Copy from a linear buffer to an SG list * sg_copy_from_buffer - Copy from a linear buffer to an SG list